Spirit-level.



PATENTBD JUNE 9, 1903.

No; 730,487. v P. B. SMITH.

SPIRIT LEVEL. APPLIUATION Hum mm 19. 1902.

no MODEL.

INVENTOR WITNESSES: y I

Patented June 9, 1903.

PA ENT I Ounce.

PUTNAM- D. SMITH, OF WATERLOO, IOWA.

SPlRlT-LEVEL SPECIFICATION forming part of Letters Patent No. 730,487,dated June 9, 1903.

Application filed August 19 1902.

['0 all whom it may concern.-

Be it known that I, PUTNAM D. SMITH, a citizen of the United States ofAmerica, and a resident of Waterloo, Blackhawk county, Iowa, haveinvented certain new and useful Improvements in'Spirit-Levels, of whichthe following is a specification.

My invention relates to improvements in spirit-levels; and the object ofmy improvement is to greatly in crease the responsiveness of theinstrument to slight changes of level by controlling its action throughthe oscillation of a weight connected to it by compound levers. Thisobject I attain by the mechanism which is illustrated in theaccompanying drawings, in which Figure 1 is a side elevation of myimproved weight-controlled spirit-level as detached from its frame. Fig.2is an end elevation of the same with one side brace removed; and Fig. 3is an under view of the same with theweight, bottom, and side piecesdetached.

Similar letters refer to similar parts throu gh out the several views.

The top plate a and the bearing-plate b are provided with the oblongopening shown, through which the spirit-level tube 0 may be seen. Thetube 0 is fastened horizontally within the oblong frame 8, and thelatter is suspended pivotally on bolts passing through hangers dependingfrom the bearing-plate b, so as to maintain in equilibrium a horizontalposition. One end of the frame 3 is lengthened out into a dependinghook-shaped bearing-piece 19, through which from top to bottom extendsan adj ustin g-screw q. From the end of the tube 0 nearest the hook p arod r extends horizontally, movable vertically through the vertical slotin said hook p. This rod is provided medially with a flattened portioncontaining a bearing through which works the adj HStlIIg-SCIGW q. Theadjustingscrew extends outwardly through the plate a,

so as to be accessible from the outside of the level. Levers n aresuspended from pivot- The ton ueiece also Serial No. 120,187. (No modehlpasses through an opening in the bottom plate 6 and is kept in place bymeans of a pin h,which passes through a slot at its tip. Slidable sidepieces CZ engage notches in the hangers c and in the bottom piece e. Thepivot studs on which the levers n are suspended form theirfulcrums, andthe longer ends of these levers extend horizontally toward theadjusting-screw and are parallel with the long sides of the frame 5. Alink Z is pivotally suspended from a hanger attached to the plate I) andis pivoted into and forms a fulcrumsupport for one end of the lever i.The other end of the lever i is pivotally connected to one of the sidebars of the frame .9 by means of a link on. The tip of the long arm ofthe lever n on the same side is pivotally connected with the lever '17at a point inside of and close to the connection with the link Z by alink is.

The function of the suspended weight f in controlling the action of thespirit-level o is thus described: When the cylinder f has been veryexactly adjusted so that the tongue-piece 9 supports it on a lineextending through its center of 1 gravity, a very slight displacement ofthe level-box from the horizontal causes said weight to'exert amultiplying effect upon the movement of the spirit-level tube. Thiseffect is caused by means of the action of the intermediate compoundlevers. The swinging of the weight f, which is but slightly resisted bythe slidablc pieces 01, raises or lowers the long arms of the levers n,which by means of the link it raises or lowers the lever t'. Themovement communicated to the lever 21 is communicated to and raises orlowers that end of the spirit-level tube-frame s farthest from theadjusting screw q by means of the link m. The delicacy in responsivenessto slight changesof level on the part of the tube 0 is thus greatlymagnified. maybe effected by means of the adjustingscrew g, by whoseaction the rod r may be raised or lowered.

It is obvious that the method of controlling and magnifying the effectof slight changes IcO of level on the spirit-level tube by means of aweight and intermediate levers 'is the es- Exact adjustments of theframes be necessary to adopt in varying forms of levels will still becomprehended in the scope of my invention. v

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is-

1. A weight-controlled spirit-level, composed of a tube mounted within apivotallybalanced frame, a pivotally-balanced frame, a compound leverconnected to said frame and to a suspended tongue-piece, a suspendedtongue-piece and a weight supported by said tongue-piece, substantiallyas shown and described.

2. A weight-controlled spirit-level, composed of a tube mounted within apivotallybalanced frame, a pivotally-balanced frame, a compound leversuspended intermediately between said frame and a weight, a weight andmeans for supporting it, all having suitable connections and supports,substantially as shown and described.

A weight-controlled spirit-level, composed of a tube mounted within apivotallybalanced frame, a pivotally-balanced frame, means for adjustingsaid frame, a compound lever suspended intermediately between said frameand a weight, a weight and means for supporting it, all having suitableconnections and supports, substantially as shown and described.

4. A weight-controlled spirit-level, composed of a casing a, aspirit-tube o mounted in a frame 5 pivotally supported from said casinga, a pivotally-balanced frames, a depending slotted bearing-piece 19extending from said frame 3, a flattened bearing-rod 0" attached to saidspirit-tube 0 and an adj usting-screw q adapted to work within said rod7' and piece p, a compound lever consisting of the parts m, i and kfulcrumcd in a link Z suspended from said casing a and connectedintermediately between said frame 8 and a pivoted hanger n, a hanger npivotally sup ported by said casing a, having a tongue-piece g, pin hand detachable plate 2 and weight f, and slidable side pieces (I,substantially as shown and described.

Signed at Waterloo, Iowa, this 12th day of August, 1902,

PUTNAM D. SMITH.

WVitnesses:

J. F. ALLERECHT, M. E. KENNEDY.

